Abstract

Design a secure public key encryption scheme and its security proof are one of the main interests in cryptography. In 2004, Canetti, Halevi and Katz [8] constructed a public key encryption (PKE) from a selective identity-based encryption scheme with a strong one-time signature scheme. In 2005, Boneh and Katz [6] improved Canetti-Halevi-Katz construction by replacing a strong one-time signature with a message authentication code, but it is not publicly verifiable. Later, Boyen, Mei and Waters [7] constructed PKE scheme directly from Waters’ IBE scheme [17] , which is only secure against direct chosen-ciphertext attack and is not secure against adaptive chosen-ciphertext attack. In 2006, Tan [16] further improved the efficiency of Canetti-Halevi-Katz (CHK) construction by directly from Boneh-Boyen identity based encryption (IBE) scheme [4] with a weak one-time signature. In this paper, we construct an efficient public key encryption scheme without one-time signature, which preserves a publicly verifiable property and secure against adaptive chosen-ciphertext attack. The construction of the proposed scheme is based on Boneh-Boyen identity-based encryption (IBE) scheme [2] and a trapdoor function. We also show that the proposed scheme is more efficient than CHK construction.